In vivo chronic scaffolding force of a resorbable magnesium scaffold

The aim of this study is to qualitatively characterize the in vivo chronic scaffolding force of the Magmaris® Resorbable Magnesium Scaffold (RMS). This important parameter of scaffolds must be balanced between sufficient radial support during the healing period of the vessel and avoidance of long-term vessel caging. A finite element model was established using preclinical animal data and used to predict the device diameter and scaffolding force up to 90 days after implantation. To account for scaffold resorption, it included backbone degradation as well as formation of discontinuities as observed in vivo. The predictions of the model regarding acute recoil and chronic development of the device diameter were in good agreement with the preclinical data, supporting the validity of the model. It was found that after 28 and 90 days, the Magmaris® RMS retained 90 % and 47 % of its initial scaffolding force, respectively. The reduction in scaffolding force was mainly driven by discontinuities in the meandering segments. Finite element analysis combined with preclinical data is a reliable method to characterize the chronic scaffolding force.